Park experienced right hamstring issues last September while with the Phillies but healed in time to join the club for the National League Championship Series and World Series, during which his pitching piqued the Yankees' interest.
Girardi said that Park might have been ready to pitch as soon as next week for the series at Oakland, but the prior hamstring issue influenced the decision.
Park felt that he might have been able to pitch in three or four days but understands why the Yankees want to be cautious.
"It's not really hurt. It's just a little sore," Park said. "They asked me to just think about the DL for 15 days and I'll be 100 percent ready. That's the idea."
Logan, 25, had a 1.35 ERA in three appearances at Triple-A after making a strong bid to open the year on the Yankees' roster as a second lefty to complement Damaso Marte.
Girardi said that a mechanical adjustment Logan made involving his leg kick, which is now more straight up and down over the rubber, helped his velocity and consistency this spring. In 10 1/3 Grapefruit League innings spanning 10 appearances, he had a 1.74 ERA.
"He pitched extremely well for us," Girardi said. "He just happened to be in a situation where we have an extremely deep bullpen. I think he would have been on a lot of other clubs, the way he pitched in Spring Training. This is an opportunity for him, and it gives us another left-hander, but I will use him against right-handers as well."
Girardi has been trying to sort out his bullpen mix over the first nine games, and Park's injury tosses in a new wrinkle. No longer can the Yankees ask three innings of Alfredo Aceves, for example, knowing that Park would be available to pitch a longer outing the next day.
"It changes it a little bit," Girardi said. "It gives guys different opportunities now in some of those innings." -- Bryan Hoch